I'm balancing on my head, and I don't think I've ever been more relaxed. I am one of about 30 women who have assumed similarly vertical positions early on a Sunday morning in a yoga studio on New York's Upper East Side. Tibetan chants and dimmed lights block out the city's chaos just beyond the door. Motivational quotes painted on the walls — jealousy works the opposite way you want it to! — seep into my consciousness.

I'm balancing on my head, and I don't think I've ever been more relaxed. I am one of about 30 women who have assumed similarly vertical positions early on a Sunday morning in a yoga studio on New York's Upper East Side. Tibetan chants and dimmed lights block out the city's chaos just beyond the door. Motivational quotes painted on the walls — jealousy works the opposite way you want it to! — seep into my consciousness.